Method and system for part measurement and verification

ABSTRACT

A system for part measurement and verification is disclosed. The system comprises a set of design criteria specifying a part and a fixture with gage blocks for positioning the part, where each of the gage blocks represents a known position. At least one probe is operable to measure the scalar values of the part and the gage blocks. A handheld information processor or computer is coupled to the probe for receiving the measurements and is operable to transform the measurements and compare those measurements to the design criteria to in order to verify the part.  
     A method for part measurement and verification is disclosed. The method comprises eight steps. Step one calls for specifying the part with a set of design criteria. Step two requires storing the design criteria in a handheld information processor. Step three provides placing the part in a fixture with gage blocks at known locations. In step four, the method provides for configuring the handheld information processor to receive part measurements. The next step calls for measuring the part with a handheld probe to generate part measurements. Step six calls for receiving the generated part measurements in the handheld information processor. Step seven requires transforming the generated part measurements to a different reference frame. The last step calls for comparing the transformed part measurements to the design criteria in order to generate a part verification report.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is a divisional of U.S. application Ser. No.09/351,032, filed Jul. 9, 1999, by Clifton Dale Cunningham, JamesMcKinnon Fitch, James Jeffery Howard, James Paul Koesters, Michael AlanLeenhouts and Eric Dewayne Moore and entitled “Method and System forPart Measurement and Verification”.

TECHNICAL FIELD OF THE INVENTION

[0002] This invention relates generally to the field of qualityassurance and, more specifically, to a method and system for partmeasurement and verification.

BACKGROUND OF THE INVENTION

[0003] Parts manufacturers must inspect individual parts to ensure thatthey meet the appropriate design criteria. Moreover, the growingcomplexity of modem manufacturing technology places increasingly higherdemands on industrial measurement and verification systems. Knownmethods of measurement and verification, however, have not beencompletely satisfactory with respect to accuracy, speed, and ease ofuse.

[0004] Known methods of inspecting manufactured parts include usingsingle dimension measurement systems, coordinate measurement machines,and laser tracking systems. Known single dimension measurement systemsinvolve two separate stages: data acquisition and data analysis. In thedata acquisition stage, a measurement probe is placed in a gage block tomeasure a part feature. The result of the data acquisition stage is alist of features and their measurements. In the data analysis stage, themeasurement data is taken to a separate computer where it is analyzed.The computer must first transform the measured data to a format andreference frame compatible with the data describing the design criteria.Next, a comparison of the measurement of each feature with the designcriteria is made to verify that the feature meets the design criteria.One of the problems associated with this approach is that it requirestwo or more separate systems, at least one for data acquisition andanother one for data analysis. A third system may be required to performthe data transformation. Another problem is that there is a time delaybetween when the data is acquired to when it is analyzed to verify thepart. A third problem is that the known single measurement systems arenot sufficiently accurate for applications requiring very high degreesof precision, such as is called for in the manufacture of aircraft. Whenanalyzing the data, the measurement is assumed to have been taken from aparticular location marked by the gage block. If the gage block is notat that location or has been moved, the measurement will not beaccurate.

[0005] Coordinate measurement machines (CMMs) measure manufactured partsusing contact probes. Typical CMMs comprise one or more probes that arecoupled to a horizontal surface on which the part to be measured isplaced. CMMs often use control panels to move the probe across the partand computer terminals to provide the measurement results. One problemwith using CMMs is that the part to be inspected must be carried to theCMM itself. Large or bulky parts may be difficult to carry to the CMM,and carrying parts from different parts of the manufacturing facility tothe CMM may be time consuming and inefficient.

[0006] A laser tracker is a portable device that uses lasers to takemeasurements of a manufactured part. Laser trackers offer an advantageover CMMs in that they can be taken to the part to be measured. Inaddition, laser trackers can be used to measure parts that are too largeto be placed on a CMM. A problem with a laser tracker, however, is thatit requires a direct line of sight in order to be able to measure apart. Many parts may be placed in fixtures, causing an area of a part tobe hidden such that there is no direct line of sight that the lasertracker can use to measure the area. Moreover, with some oddly shapedparts, the laser tracker may need to be maneuvered in an inconvenientmanner in order to take measurements.

[0007] While these devices and methods have provided a significantimprovement over prior approaches, the challenges in the field ofquality assurance have continued to increase, with demands for more andbetter techniques having greater flexibility and adaptability.Therefore, a need has arisen for a new method and system for partmeasurement and verification.

SUMMARY OF THE INVENTION

[0008] In accordance with the present invention, a method and system forpart measurement and verification are provided that substantiallyeliminate or reduce the disadvantages and problems associated withpreviously developed systems and methods.

[0009] A system for part measurement and verification is disclosed. Thesystem comprises a set of design criteria specifying a part and afixture with gage blocks for positioning the part, where each of thegage blocks represents a known position. At least one probe is operableto measure the scalar values of the part and the gage blocks. A handheldinformation processor or computer is coupled to the probe for receivingthe measurements and is operable to transform the measurements andcompare those measurements to the design criteria in order to verify thepart.

[0010] A method for part measurement and verification is disclosed. Themethod comprises eight steps. Step one calls for specifying the partwith a set of design criteria. Step two requires storing the designcriteria in a handheld information processor. Step three providesplacing the part in a fixture with gage blocks at known locations. Instep four, the method provides for configuring the handheld informationprocessor to receive part measurements. The next step calls formeasuring the part with a handheld probe to generate part measurements.Step six calls for receiving the generated part measurements in thehandheld information processor. Step seven requires transforming thegenerated part measurements to a different reference frame. The laststep calls for comparing the transformed part measurements to the designcriteria in order to generate a part verification report.

[0011] In another method for part measurement verification, there aresix steps. The first step calls for storing a digital representation ofa part in a memory. The second step calls for configuring the logic unitto read data from the probe representative of part measurement. Stepthree requires receiving the probe data. Step four provides forgenerating part measurements from the probe. Step five calls fortransforming the part measurement from the first reference frame to asecond reference frame. The final step calls for comparing thetransformed part measurement to the digital representation to verify thepart.

[0012] Another system for part measurement and verification isdisclosed. The system comprises a belt operable to be worn by a user.There are one or more pouches fixed to the belt and adapted to receive aprobe. A wiring harness contained within the belt has couplers toconnect the probe to an information processor.

[0013] A technical advantage of the present invention is that a systemand method for part measurement and verification is provided that iscapable of real time data measurement, acquisition, analysis,verification and reporting of inspection results. Another technicaladvantage of the present invention is that it is a self-contained,highly portable tool-based inspection system. Another technicaladvantage is that the present invention provides more flexible andadaptable part measurement and verification. Another technical advantageof the present invention is that it can be performed in software on asingle information processor. Another technical advantage is that thepresent invention provides a single system that is entirely contained ona belt to be worn by an individual user.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] For a more complete understanding of the present invention, andfor further features and advantages, reference is now made to thefollowing description, taken in conjunction with the accompanyingdrawings, in which:

[0015]FIG. 1 is a system block diagram of one embodiment of the presentinvention;

[0016]FIG. 2 is a flowchart demonstrating one method of measurement andverification in accordance with the present invention;

[0017]FIG. 3A illustrates a perspective view of one embodiment of a partcoupled to a fixture;

[0018]FIG. 3B illustrates an underside view the part and fixture of FIG.3A;

[0019]FIG. 3C is the view 3C-3C of FIG. 3B, illustrating, in greaterdetail, a gage block coupled to a fixture;

[0020]FIG. 3D illustrates, in greater detail, the gage block of FIG. 3C;

[0021]FIG. 3E is the view 3E-3E of FIG. 3B, illustrating, in greaterdetail, a gage block and a part;

[0022]FIG. 4 illustrates one embodiment of a one-dimensional probe and agage block;

[0023]FIG. 5A illustrates one embodiment of a two-dimensional probe anda gage block;

[0024]FIG. 5B illustrates, in greater detail, the two-dimensional probeof FIG. 5A;

[0025]FIG. 6A illustrates one embodiment of a belt in accordance withone embodiment of the present invention;

[0026]FIG. 6B illustrates, in greater detail, a top view of a pouch ofthe belt of FIG. 6A;

[0027]FIG. 6C illustrates, in greater detail, a side view of a pouch ofthe belt of FIG. 6A;

[0028]FIG. 6D illustrates, in greater detail, a front view of a pouch ofthe belt of FIG. 6A;

[0029]FIG. 7 is a wiring diagram for one embodiment of an informationprocessor and a field wiring assembly;

[0030]FIG. 8 is a flowchart demonstrating one method of measurementanalysis in accordance with the present invention; and

[0031]FIG. 9 is a flowchart demonstrating, in greater detail, one methodof measurement analysis in accordance with the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0032]FIG. 1 is a system block diagram of one embodiment of the presentinvention. In this embodiment, a part 102 to be measured and verified isplaced on a fixture 104. The part 102 may be anything, for example, theupper bonnet of an airplane fuselage or the side panel of an automobile.The fixture 104 may be, for example, a fixed assembly jig. The fixture104 includes one or more gage blocks 106. A gage block 106 is designedto hold and position a probe 108 used to measure the part 102. The gageblocks 106 are described in more detail in connection with FIGS. 3C, 3Dand 3E. The probes 108 are described in more detail in connection withFIGS. 4, 5A, and 5B. In this particular embodiment, up to six probes 108may be used to measure the part 102. Each probe 108 performs a scalarmeasurement and generates an electrical signal representation of thatmeasurement. The probes 108 are coupled by cables 110 to a field wiringassembly 112, which is described in further detail in connection withFIG. 7. A belt 114, which is described in more detail in connection withFIGS. 6A, 6B, 6C, and 6D, holds the probes 108 and the field wiringassembly 112. A cable 116 couples the field wiring assembly 112 to aninformation processor 118. The information processor 118 can be anoff-the-shelf personal computer adapted for use in the presentinvention. It may be a handheld computer, for example, a Telxon PTC 1194computer with a National Instruments DAQ 500 analog-to-digital card. Theinformation processor 118 comprises an analog digital card 120, aprocessor 122, a memory 124, at least one input device 126, and adisplay 127. The analog-to-digital card 120 converts the analogmeasurements received from the probes 108 to digital data. The processor122 processes data, the memory 124 stores data, and the input device 126is used by the user to interact with the information processor 118.Display 127 provides visual information to the user.

[0033]FIG. 2 is a flowchart demonstrating one method of measurement andverification in accordance with the present invention. The method beginswith step 202, where the part 102 to be measured and verified isspecified with a set of design criteria. The design criteria may be, forexample, the specifications for the part, and may be part of aninspection data set (IDS), which may be, for example, a protectedMicrosoft™ Excel disk file. The design criteria may originally have beencreated using computer aided design software such as CATIA. The designcriteria may be expressed in the part reference system, which, by way ofexample, may be a part for an aircraft. The design criteria may also bespecified in a third reference frame, which in this example, would bethe aircraft reference frame. The design criteria are stored in aninformation processor 118, as stated in step 204. In step 206, the part102 is placed in a fixture 104. The fixture includes gage blocks 106,which are used to position the probes 108 that measure the part. In step208, the position and direction of each gage block 106 is determined.The position and direction data may be expressed with respect to, forexample, the fixture reference frame, and may be part of the IDS file.

[0034] The method then proceeds to step 210, where the informationprocessor 118 is configured to receive part measurements. In step 212,the positions of the part datum and part features are measured using theprobe 108. Part datums are used to align the part, and part features areused to compare the part to the design criteria. The informationprocessor 118 receives these measurements, as stated in step 214.

[0035] The method then proceeds to step 216, where transformationequations are calculated from the part datum positions. Thetransformation aligns the part datums with their associated nominalpositions by transforming the coordinates from the fixture referenceframe to the part reference frame. For example, if a particular partdatum is supposed to have the coordinate (0,0,0), the transformationwill assign that coordinate to the datum. This transformation is appliedto eliminate deviations between the part datums and their associatednominal positions that may have occurred while placing the part on thefixture. If the design criteria are expressed in the part referenceframe, the measurements may be compared with the criteria once they havebeen transformed to this reference frame. In this particular embodimentof the invention, the design criteria are expressed in the aircraftreference frame, so another transformation is applied to transform themeasurement data from the part reference frame to the aircraft referenceframe. After the transformation equations are calculated, the methodproceeds to step 218, where the positions are transformed from thefixture reference frame to the part reference frame using thetransformation equations calculated in step 216. In step 220, thepositions are transformed from the part reference frame to the aircraftreference frame, in order to express the measurements in the referenceframe of the design criteria. The transformation equations for thistransformation are fixed, and may be included, for example, in the IDSfile.

[0036] After the measured positions have been transformed to the samereference frame as that of the design criteria, the method proceeds tostep 222, where the measured positions are compared to the designcriteria in an order to verify the part 102. The information processor118 verifies whether the measured positions fall within the acceptablerange as specified by the design criteria. Finally, the method proceedsto step 224, where the information processor 118 generates a partverification report. The part verification report may state, forexample, the measurements of the part features and whether themeasurements fall within the acceptable range of the design criteria.

[0037]FIG. 3A illustrates a perspective view of one embodiment of a part102 coupled to a fixture 104. In this example, the part 102 is the upperbonnet of an airplane fuselage. The fixture 104 is a floor assembly jig.FIG. 3B illustrates an underside view of the part 102 and fixture 104 ofFIG. 3A. The figure shows three groups of three gage blocks 106 a-106 icoupled to a fixture rib 302 near the forward edge of the part and twogage blocks 106 j and 106 k coupled to a fixture rib 304 near theforward corner of the panel. The gage blocks 106 a-106 k position theprobes that are used to measure the part 102. FIG. 3C is a view alongthe line 3C-3C of FIG. 3B illustrating, in greater detail, gage blocks106 a-106 i and a fixture rib 302. Three groups of three gage blocks 106a-106 i are coupled to the fixture rib 302. FIG. 3D presents an enlargedview of a probe 108 coupled to the gage block 106 e of FIG. 3C. Theprobe 108 may be, for example, a TP107-EP100 probe, manufactured by MPComponents. The TP107-EP100 probe is a single axis device used to locateand measure the stringer centerline 310. The measurements collected fromthis probe represent the linear deviation of the stringer centerlinefrom a known reference point.

[0038]FIG. 3E is the view along the line 3E-3E of FIG. 3B illustrating,in greater detail, gage blocks 106 j and 106 k and a part 102. Theprobes 108 and 109 are coupled to gage blocks 106 j and 106 k,respectively, coupled to fixture rib 304. The probes 108 and 109 may be,for example, 200-SB probes, manufactured by Linear MeasurementsInstruments (LMI). The 200-SB probe is a single axis device used tomeasure linear displacement and has a range of approximately 10 mm. Theprobe is positioned to measure a feature location using a gage block,coupled to a bracket and a bushing. The probes 108 and 109 are coupledto brackets 320 and 322, respectively, and bushings 324 and 326,respectively. The brackets may be, for example, LMI 264 brackets. Theindex bushings may be, for example, LMI 1261 index bushings, which arestandard ⅜ inch diameter threaded bushings. One probe 108 measures theedge of part 328, and the other probe 109 measures the molding line 330of the part.

[0039]FIG. 4 illustrates one embodiment of a one-dimensional probe 108and a gage block 106. The probe 108, which is coupled to an indexbushing 324 of a gage block 106, measures a part feature 402 of a part102. The gage block position (x_(g), y_(g), z_(g)) and direction (i, j,k) 404 are expressed in the fixture reference frame. The nominal setback406 is the distance from the gage block (x_(g), y_(g), z_(g)) 404 to thetip of the probe. The probe measures the scalar distance 408 from theprobe tip to the part feature 402. Examples of one-dimensional scalarmeasurement probes include the TP107-EP100 probe, manufactured by MPComponents, and the 200-SB probe, manufactured by LMI.

[0040]FIG. 5A illustrates one embodiment of a two-dimensional probe 108and a gage block 106. The probe 108, which is located in a gage block106, measures the part feature 402 of a part 102. FIG. 5B illustrates,in greater detail, the two-dimensional probe 108 of FIG. 5A measuring apart feature 402. The gage block position 502 and direction 504 areexpressed in the fixture frame of reference. The probe measures thevertical 506 and horizontal 508 displacement of the part feature 402.Examples of two-dimensional scalar measurement probes include the TP107and the TP108 probes, both manufactured by MP components, which are usedto locate the center line of panel reference holes and to measure thetwo-dimensional deviation of the part reference hole from a knownreference point.

[0041]FIG. 6A illustrates one embodiment of a belt 114 in accordancewith one embodiment of the present invention. Nine pouches 604 arecoupled to a waistband 602, which may be designed to fit around a user'swaist and is operable to be worn by the user. Note that the pouches areof different shapes to hold different types of probes 108. Waistband 602and pouches 604 may be constructed of fabric, leather or any appropriateweb material. A field wiring assembly 112, which is discussed in moredetail in connection with FIG. 7, is coupled to the waistband 602. FIG.6B illustrates, in greater detail, a top view of a pouch 604 of the beltof FIG. 6A. The pouch 604 is coupled to the waistband 602 by a pouchloop 610. FIG. 6C illustrates, in greater detail, a side view of a pouch604 of the belt of FIG. 6A. In this cutaway illustration, a probe 108 isshown inside the pouch 604. The pouch 604 is coupled to the waistband602 by a pouch loop 610. The belt includes a Velcro wire conduit 612,which provides wiring for the probe 108. A feed-through hole 614provides a path through which wiring from the Velcro wiring conduit 612is coupled to the probe 108. A probe loop 616 is used for holding theprobe 108 securely in the pouch 604. The pouch 604 may include a flap618 for securing a probe 108 in the pouch 604. FIG. 6D illustrates, ingreater detail, a front view of a pouch 604 of the belt of FIG. 6A. Theflap 618 is shown closing the pouch 604.

[0042]FIG. 7 is a wiring diagram for one embodiment of an informationprocessor 118 and a field wiring assembly 112. The information processor118 is coupled to the field wiring assembly 112 with a cable 116. Theinformation processor 118 may be, for example, a Telxon PTC 1194hand-held computer, and includes an analog-to-digital card 120, aconnector 704, a cable 706, and a transition board 708. Theanalog-to-digital card 120 may be, for example, a National InstrumentsDAQ 500 card. The connector 704 may be a commercially-availableconnector for the DAQ 500. The cable 706 may be, for example, a NationalInstruments PR27-30F cable. The transition board 708 converts a signalfrom the DAQ 500 to RJ48. The cable 116 coupling the informationprocessor 118 to the field wiring assembly 112 may be a 10-conductor,silver satin telcom cable. The field wiring assembly 112 providesexcitation to the probes and receives signals from the probes. The fieldwiring assembly 112 may be coupled to the belt 114 of FIG. 1, andincludes a diode 720 and probe connectors 722. The diode 720 conditionsthe signal. The probe connectors 722, which may be RJ10 or RJ12connectors, couple the probes 108 of FIG. 1 to the field wiring assembly112.

[0043]FIG. 8 is a flow chart demonstrating one method of measurementanalysis in accordance with the present invention. The method beginswith step 802, where a digital representation of a part 102 is stored ina memory 124. The digital representation may be, for example, the designspecifications of the part. The memory may be, for example, part of aninformation processor 118. In step 804, a logic unit is configured toread data from a probe 108. The logic unit may be, for example, themicroprocessor of an information processor 118. The probe 108 may be,for example, any of the probes described in connection with FIGS. 4, 5A,and 5B. In step 806, the logic unit receives the probe data. The probedata may be analog signals representative of measurements of the part102 to be verified. The method then proceeds to step 808, where the partmeasurements are generated from the probe data. In step 810, the partmeasurements are transformed to align the actual datum positions withthe nominal part datums, that is, to align an actual coordinate systemwith the nominal part. The measurements may be transformed again inorder to place them in the reference frame in which the digitalrepresentation of the part is expressed, because often the designcriteria will be given in a reference frame different from that in whichthe measurements are expressed. Finally, in step 812, the partmeasurements are compared to the digital representation to verify thepart.

[0044]FIG. 9 is a flowchart demonstrating one method of measurementanalysis and verification in accordance with the present invention. Anembodiment of this method may be written in Visual Basic 5.0 designedfor Microsoft™ Windows. An embodiment may provide a graphical interfacethat provides the user with a display with which the user may interact(for example, receive or input information) with the system during astep in the method. The method begins with step 901, where the userselects to create a new measurement job, open an existing measurementjob, send a measurement job, print a measurement job, or exit theprogram. If the user selects to create a new job (step 902), then themethod proceeds to step 904, where the user selects an IDS file. An IDSfile, which may be, for example, a protected Microsoft™ Excel file, isspecific to a particular fixture 104 and a particular part 102. An IDSfile may contain: (1) the three-dimensional position and direction ofeach gage block 106 with respect to, for example, the fixture referencesystem (the XYZ coordinate system); (2) part datum criteria, which arethe nominal positions of the part datum in the part reference system(the X′Y′Z′ coordinate system); (3) part feature criteria, which are thedesired positions of the part features expressed in the aircraftreference system (the X″Y″Z″ coordinate system); (4) transformationequations from the X′Y′Z′ coordinate system to the X″Y″Z″ coordinatesystem; and (5) the analysis case for each feature position, whichdescribes how each feature is to be analyzed, based on the type of thefeature (e.g., hole, surface). After the user selects the IDS file, theprocess proceeds to step 905. If the user selects to open an existingmeasurement job (step 908), the method proceeds to step 910, where theuser is presented with a list of existing jobs. Once the user opens anexisting job, the method proceeds to step 905. If the user selects tosend a measurement job, print a measurement job, or exit the program(step 912), the method proceeds to step 913, where the user may completethe selected action.

[0045] In step 905, probe configuration data is stored in theinformation processor 118. The information processor 118 uses this datato determine how to collect the part measurements. The data includesprobe serial numbers, which are used by the information processor 118 todetermine the unique calibration factors of each probe 108, and computerdata channel numbers, which are used to identify the data channels towhich the probes 108 are coupled.

[0046] The method then proceeds to step 906, where the user selects theprobe types to measure the part. Examples of probe types are presentedin the discussion in connection with FIGS. 4, 5A and 5B. The method thenproceeds to step 914, where the information processor assigns a computerinput channel to each probe 108. Each probe 108 must be coupled to itsassigned computer input channel. Probes may be allowed to share computerdata channel numbers, but only one of the sharing partners can becoupled to its computer input channel at any given time. In step 916,the user records the probe zero values to establish the zero orreference point of the probe output. In step 918, the user performsfield checks on the probes in order to validate the accuracy of theprobes at the high and low end points of the measurement range.

[0047] The method then proceeds to step 920, where the position anddirection of each gage block 106 is determined. These positions may bestored in the IDS file. The position (x_(g), y_(g), z_(g)) and thedirection (i, j, k,) of each gage block 106 are expressed in the XYZcoordinate system. In step 922, a probe measures the scalar distancefrom the probe tip to its associated part datum, and the informationprocessor 118 receives the measurement. From that measurement and thenominal setback of the probe, the distance s_(d) from the gage block106, located at (x_(g), y_(g), z_(g)), to its associated part datum canbe computed. In step 924, the user measures the overconstraint point(the OCP), which is used to validate whether the part can be inspectedas supported in the fixture, that is, the part is not racked, warped, ortwisted. The information processor 118 receives this measurement. Theuser checks to see that the OCP position is within the toleranceguidelines. In step 926, a probe measures the scalar distance from theprobe tip to its associated part feature, and the information processor118 receives the measurement. From that measurement and the nominalsetback of the probe, the distance s_(f) from the gage block 106,located at (x_(g), y_(g), z_(g)), to its associated part feature can becomputed.

[0048] The method then proceeds to step 928, where the part datum andpart feature positions are calculated in the XYZ coordinate system.Given the gage block position (x_(g), y_(g), z_(g)) and direction (i, j,k) and the distance Sd between the gage block and the part datum, thepart datum position (x_(d), y_(d), z_(d)), can be calculated using adistance formula. The part feature positions can be calculated in asimilar manner.

[0049] The method then proceeds to step 930, where the transformationequations from the fixture reference frame (the XYZ coordinate system)to the part reference frame (the X′Y′Z′ coordinate system) arecalculated. The transformation equations are calculated by comparing themeasured positions of the part datums with their corresponding nominalpositions. In step 932, the transformations equations are applied. Thetransformation serves to align the actual part datums with theircorresponding nominal positions. For example, suppose that a datum holeis supposed to be located at (0, 0, 0). If the hole does not have thecoordinate (0, 0, 0) in the XYZ coordinate system, the transformationwill transform its coordinates to (0, 0, 0) in the X′Y′Z′ coordinatesystem. In step 934, the coordinates are transformed from the X′Y′Z′coordinate system to the X″Y″Z″ coordinate system. The transformationequations for this transformation may be contained in the IDS file. Thistransformation serves to express the coordinates of the part positionsin the aircraft reference frame, the frame in which the design criteriaare expressed.

[0050] The method then proceeds to step 938, where the measured partfeature positions are compared with the design criteria in order toverify the part. The information processor 118 checks whether thepositions of the part features fall within the tolerance rangesspecified by the design criteria. Finally, after the features arechecked, the method proceeds to step 940, where a part verificationreport is generated. The part verification report may be, for example, aMicrosoft Word document that contains the measured and calculated partfeature data and whether the part feature satisfies the design criteria.

[0051] Although an embodiment of the invention and its advantages aredescribed in detail, a person skilled in the art could make variousalternations, additions, and omissions without departing from the spiritand scope of the present invention as defined by the appended claims.

What is claimed is:
 1. A system for part measurement and verification,the system comprising: a) A belt operable to be worn by a user; b) Oneor more pouches fixed to the belt and adapted to receive a probe; and c)A wiring harness, contained within the belt, having couplers to connectthe probes to an information processor.
 2. The system of claim 1 whereinthe belt is constructed of a fabric.
 3. The system of claim 1 whereinthe pouches are adapted to accommodate different probes.
 4. The systemof claim 1 wherein at least one coupler is a probe coupler for couplingthe probes to the wiring harness.
 5. The system of claim 1 wherein eachpouch has a probe coupler.
 6. The system of claim 1 wherein there are aplurality of pouches and there is one probe coupler for each pouch. 7.The system of claim 1 wherein there is a second coupler fixed to thebelt for coupling the information processor to the wiring harness. 8.The system of claim 1, wherein the wiring harness is operable to receivea signal from a probe and transmit the signal to an informationprocessor, and further operable to receive a signal from the informationprocessor and transmit the signal to the probe.
 9. The system of claim8, wherein the wiring harness further comprises a diode operable tocondition the signal.